Dry-spinning of halogenated aromatic polyesters (i.e., spinning of a solution of the polymer into an atmosphere evaporative for the solvent) is a well-known method for forming shaped articles such as fibers of the polymeric material.
In a typical commercial dry-spinning operation, a polymer containing solution is dry-spun by extruding the solution through a plurality of openings or jets into a spinning column where the solvent is evaporated. During the extrusion process, a static charge, or spin-line static may tend to build up on the extruded fibers. Under certain extrusion conditions a streaming potential E is developed at the spinneret which, in turn, generates a static charge on the extruded fibers sufficient to induce a phenomonon known as spraying. For example, a polyester of the type described herein when dissolved in 100% methylene chloride yields a solution which has a low specific conductance (.lambda.). When this solution is dry-spun through a metal jet to form fibers in a typical dry-spinning operation electrons are either stripped from, or transferred to, the metal capillary walls by the liquid stream undergoing extrusion. This transfer of electrons develops what is referred to as streaming potential which in turn generates a static charge or spin-line static on the exit stream of fibers sufficient to cause spraying of the fibers. "Spraying" describes the behavior of the fibers at the jet in which they are mutually repelled by the static charges present thereon. The extent of the charge on the fibers during extrusion can be measured with an electrostatic voltmeter which is a relative measure of the streaming potential, E.
If the spin-line static charge is strong enough it will repel the fibers with a force sufficient to cause them to strike the wall of the metier cabinet (i.e., evaporating chamber) thereby interrupting the extrusion process.
It is known to add sterically hindered phenols to polyesters for color stabilization illustrated by U.S. Pat. Nos. 3,669,927; 3,285,855 and British Pat. No. 1,107,832.
It is therefore an object of the present invention to provide an improved process for dry-spinning certain halogenated aromatic polyesters to yield fibers having reduced spin-line static generation.
It is a further object of the present invention to provide a solution which is adaptable to form fibers via dry-spinning having reduced spin-line static generation.
It is a still further object of the present invention to provide a composition adaptable for use in a dry-spinning process utilized to prepare certain halogenated aromatic polyester fibers having reduced spin-line static generation.
These and other objects as well as the scope, nature and utilization of the invention will be apparent to those skilled in the art from the following description and appended claims.